<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>select</title>
    <script type="text/javascript">
        window.onload=function () {
            document.getElementById("incommon").value =
                document.getElementById("mylist").options[0].text;
            document.getElementById("mylist").onchange = function () {
                document.getElementById("incommon").value =
                    document.getElementById("mylist").options[document.getElementById("mylist").selectedIndex].text;
            }
            document.getElementById("btn").onclick = function () {
                movenum();
            }
        }
        function movenum() {
            var numm=document.getElementById("num");
            var opt=numm.options[numm.selectedIndex].text;
            var str=document.getElementById("result").value;
            str+=opt;
            document.getElementById("result").value=str;
        }

    </script>
</head>
<body>
<form>
    <label>选择常用的浏览器：</label>
    <select id="mylist">
        <option>internet explore</option>
        <option>chrome</option>
        <option>firefox</option>
    </select><br>
    <label>常用的浏览器是：</label>
    <input type="text" id="incommon" size="20">
</form>
<form>
    <label>选择数字：</label>
    <select id="num">
        <option>0</option>
        <option>1</option>
        <option>2</option>
        <option>3</option>
        <option>4</option>
        <option>5</option>
        <option>6</option>
        <option>7</option>
        <option>8</option>
        <option>9</option>
        <option>10</option>
    </select>
    <input type="button" id="btn" value="&gt&gt;">
    <input type="text" id="result" size="20">
</form>

</body>
</html>